In this thesis, a training sequence set for a multiple-input and multiple-output (MIMO)system adopting a training-sequence scheme is proposed. The training sequence set is derivedusing the least-square approximation (LSA) and named partial-period zero-correlation zone(PZCZ) sequence set because of its correlation property. A PZCZ sequence set achievesminimum mean-square error (MMSE) in a frame structure in which training sequences areplaced ahead of information.The properties of PZCZ sequence sets and the methods of designing and extending thesequence set are also given.Index Terms ？ Autocorrelation function, cross-correlation function, least-squareapproximation, partial-period correlation, zero-correlation zone sequence set.